1. Field
The present disclosure relates generally to aircraft and, in particular, to landing sites for aircraft. Still more particularly, the present disclosure relates to a method and apparatus for describing a route to a landing site using a formal language.
2. Background
Commercial aircraft have planned routes from an originating airport to a destination airport. However, during the flight of an aircraft, events may result in the use of a different landing site other than the destination airport. This alternative landing site may be, for example, an alternate airport. Events such as thunderstorms, inconsistencies in the aircraft, changes in usable airspace, issues at the destination airport, and other events may result in an alternate landing site being selected for the aircraft.
Although a pilot of an aircraft is highly trained in emergency procedures, the pilot may be focused on tasks other than selecting an alternate landing site. For example, the pilot may be focused on managing flight of the aircraft in heavy turbulence, flying the aircraft with an undesired configuration, or on some other task. These and other situations may be stressful and may require more attention from the pilot than desired.
The pilot may assess the available landing site options that are in range of the aircraft and select one of these landing sites from the pilot's prior experience. The pilot may then find a way to fly the aircraft to the selected landing site avoiding terrain, no-fly zones, other aircraft, and other obstacles that may be present in reaching the selected landing site.
Currently, this burden of assessing landing sites and routes to landing sites is placed on the pilot with some potential help from an air traffic controller. The air traffic controller may provide assistance through the knowledge of the overall state of the airspace around the aircraft. Additionally, other aides may be present, such as navigation systems, which may select the nearest airport to the current location of the aircraft.
These types of systems, however, do not take into account potential intervening terrain, no-fly zones, weather conditions, and other obstacles. The navigation systems may only provide a simple direct point-to-point route for the aircraft.
Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.